A semiconductor device 101 is disclosed, for example, in Japanese Patent Application Publication No. 2001-227902 (i.e., U.S. Pat. No. 6,316,840). The device 101 includes a sensor module 111 for detecting physical quantity such as acceleration, pressure and angular rate, as shown in FIG. 17. The sensor module 111 provides an acceleration sensor, a pressure sensor or an angular rate sensor. In the sensor module 111, a movable portion 50 is disposed on a principal plane of a sensor substrate, i.e., a sensor chip 52. The sensor chip 52 includes at least the movable portion 50 and an electric device (not shown). The electric device outputs an electric signal corresponding to a displacement of the movable portion 50. The electric signal outputted from the electric device is transmitted to a processing substrate, i.e., a signal processor 53 through a bump 21. The signal processor 53 performs a predetermined signal processing so that the physical quantity is detected.
The signal processor 53 is provided by an application specific integrated circuit (i.e., ASIC) so that the signal processor 53 calculates the physical quantity such as the acceleration, the pressure or the angular rate on the basis of the electric signal outputted from the sensor chip 52. Further, the signal processor 53 sends a predetermined control signal to the sensor chip 52 so that the movable portion 50 and the electric device are controlled electrically.
The sensor chip 52 and the signal processor 53 are mounted on a die pad 55of a lead frame. The signal processor 53 is electrically connected to an inner lead 56 through a wire 54. The sensor chip 52 and the signal processor 53 together with the die pad 55 and the inner lead 56 are sealed in a resin mold 57 so as to provide a resin mold package.
The die pad 55 of the sensor module 111 is disposed below the inner lead 56. Specifically, the die pad 55 is disposed at lower position lower than the inner lead 56 so as to provide a low die pad construction. This construction provides that the height of the inner lead 56 is almost the same as the height of semiconductor parts such as the signal processor 53 disposed on the die pad 55. Therefore, the wire 54 is easily bonded between the inner lead 56 and the semiconductor parts.
It is required to secure a movement (i.e., displacement) of the movable portion 50. Specifically, it is required for the movable portion 50 to move smoothly. In general, the movable portion 50 is covered with a casing so that the casing prevents resin composing the resin mold 57 from penetrating into the casing. However, total number of parts is increased because of the casing. Therefore, manufacturing cost is increased. Further, it is necessitated to bond the casing to the sensor chip 52. Therefore, additional manufacturing process is necessitated so that the manufacturing cost is much increased.
In view of the above problem, in the semiconductor device 101, the signal processor 53 is disposed on the die pad 55, and the sensor chip 52 is disposed on the signal processor 53. A resin sealing 70 seals between the periphery of the sensor chip 52 and the principal plane of the signal processor 53. The resin sealing 70 is disposed all around the periphery of the sensor chip 52 so that a closed spacing 71 is provided by the resin sealing 70, the sensor chip 52 and the signal processor 53. The sensor chip 52 includes multiple bumps 21 disposed on the principal plane. The bumps 21 are connected to electrodes disposed on the principal plane of the signal processor 53 so that the sensor chip 52 electrically connects to the signal processor 53. The signal processor 53 is connected to the inner lead 56 through the wire 54. Thus, the resin material composing the resin mold 57 is prevented from penetrating into the closed spacing 71 so that the movable portion 50 can move smoothly.
However, it is necessitated to protect the sensor module 111 from outside disturbance such as noise. Therefore, a shield (not shown) is necessitated for protecting the sensor module 111. The shield made of metal and the like is disposed on the sensor module 111. Thus, total number of parts of the semiconductor device 101 is increased because of the additional shield. Therefore, additional manufacturing process is necessitated so that the manufacturing cost of the device 101 is increased.